Note: Using the eclipselink-orm.xml mapping file enables many EclipseLink advanced features, but it may prevent the persistence unit from being portable to other JPA implementations.

The eclipselink-orm.xml file defines object-relational mapping metadata for EclipseLink. It is built from the existing orm.xml file which makes it more intuitive, requires minimum configuration, and makes it easy to override.

For more information, see Section 12.2 "XML Overriding Rules" in the JPA Specification.

Overriding and Merging

To override the orm.xml file's mapping, you must define the META-INF/eclipselink-orm.xml file in the project. When both orm.xml and eclipselink-orm.xml are specified, the contents of eclipselink-orm.xml override orm.xml and any other JPA mapping file specified in the persistence unit. If there are overlapping specifications in multiple ORM files, the files are merged if they are no conflicting entities.